Pseudoalteromonas pernae sp. nov., a novel bacterium with antimicrobial potential isolated from the intestinal tract of mussel genus Perna (Bivalvia: Mytilidae).

Abstract

The two bacterial strains, designated YIC-656^T and YIC-468, were isolated from the intestinal tract of Perna mussels (Bivalvia: Mytilidae) in China. Both strains were Gram-negative, aerobic, rod-shaped and motile, with a single polar flagellum. Strain YIC-656^T exhibited the highest 16S rRNA gene sequence similarity (98.4%) to strain Pseudoalteromonas ruthenica KMM300^T, followed by Pseudoalteromonas caenipelagi JBTF-M23^T and Pseudoalteromonas xishaensis E418^T, with sequence similarities of 98.3% and 98.2%, respectively. The 16S rRNA gene sequence similarity between strains YIC-656^T and YIC-468 was 99.9%, and their DNA G+C contents were both 45.3%. By genomic analyses, the average nucleotide identity and digital DNA-DNA hybridization values of strain YIC-656^T with any other related species were below 74.3% and 21.8%, while the indices between YIC-656^T and YIC-468 were 98.8% and 91.3%, respectively. These results indicate that strains YIC-656^T and YIC-468 belong to the same species and are distinct from other species within the genus Pseudoalteromonas. Phenotypic and chemotaxonomic tests further validated their differentiation from the closest relatives. The fatty acid profiles of both strains mainly (>7.0%) consisted of C_16:0, summed feature 3 (comprising C_16:1  ω7c and/or C_16:1  ω6c), summed feature 8 (comprising C_18:1  ω7c and/or C_18:1  ω6c) and C_18:0. The predominant respiratory quinone was Q-8. The polar lipids included phosphatidylethanolamine and unidentified lipids. Based on these phenotypic and genotypic results, strains YIC-656^T and YIC-468 represent a new species of Pseudoalteromonas, for which we propose Pseudoalteromonas pernae sp. nov. The type strain is YIC-656^T (=MCCC 1K08806^T=KCTC 8211^T).